Electrically driven pump

ABSTRACT

An electrically driven pump has a housing which contains the stator and rotor of an electric induction motor. A portion of the liquid urged through the pump by an impeller driven by the rotor is passed through the bearings of the pump and across the stator windings before returning to the pump inlet.

United States Patent [191 Bottoms [111 3,826,595 [451 July 30, 1974 ELECTRICALLY DRIVEN PUMP [75] Inventor: Harry Simister Bottoms, Solihull,

England [73] Assignee: Joseph Lucas (Industries) Limited,

Birmingham, England [22] Filed: Mar. 7, 1973 [21] Appl. No.: 338,959

52 Us. c1. 417/370 [51] Int. Cl. F04b 17/00 [58] Field of Search 417/370, 371

[56] References Cited UNITED-STATES PATENTS 2,321,126 6/1943 Breuer'm, 417/371 2,520,880 8/1950 Harlamoff '417/370 2,911,918 11/1959 Reed 417/370 3,220,350 11/1965 White 417/370 3,288,073 11/1966 Pezzillo 417/370 3,618,337 11/1971 Mount 417/371 3,644,067 2/1972 Yowell 417/370 Primary Examiner-C. J Husar Attorney, Agent, or Firm-Hill, Gross, Simpson, Van Santen, Steadman, Chiara & Simpson 57 ABSTRACT An electrically driven pump has a housing which contains the stator and rotor of an electric induction motor. A portion of the liquid urged through the pump by an impeller driven by the rotor is passed through the bearings of the pump and across the stator windings before returning to the pump inlet.

4 Claims, 2 Drawing lFigures PATENTEuJummM SHEET 2 [IF 2 1 ELECTRICALLY DRIVEN PUMP This invention relates to electrically driven axial-flow pumps forliquids.

According to the invention a pump of the type specitied comprises a casing having an inlet and an outlet and containing a housing which supports the stator and rotor of an electric induction motor, a shaft rotatable in bearings in the said housing and forming part of the said rotor, an impeller carried by the shaft within the inlet of the casing, an axial passage between the casing and the housing and connecting the inlet and outlet and through which, in use, the greater part of the liquid flows, and means for directing a part of the said liquid through the bearings and past the stator windings before returning it to the inlet.

A pump according to the invention will now be described by way of example and with reference to the accompanying drawings in which:

FIG. 1 shows a section through the housing; and

FIG. 2 shows a section through the pump on the line 2--2 in FIG. 1.

A casing having an inlet 8 and an outlet 9 comprises a body 11, a diffuser 12 and end members 13, 14. The body 11, diffuser 12 and end member 14 include a housing comprising inner portions l7, l8, l9 respectively which are supported by webs 20, 21, 22. The webs 20, 21, 22'define aligned axial passages 23, 24, between the casing and the housing. The body 11, diffuser 12 and end members 13, 14 are sealingly secured together by bolts 15 which extend axially of the pump through holes 16 in the webs 20, 21, 22.

The inner portion 17 of the body 11 forms a mounting for stator windings 35 of an electric induction motor. A hollow shaft 24 is rotatable in bearings 36, 38 in the inner portions 18, 19 of the diffuser 12 and end member 14 respectively and forms part of the rotor of the induction motor. Thrust bearings 27, 28 prevent axial movement of the shaft 34.

An impeller 29, of generally helical form, is secured to one end of the shaft 24 by means of a bolt 30 and a nut 31 engaging an internal shoulder on the shaft 24. The bolt 30 has a substantially conical head 32 and an axial bore 33 through which the interior of the shaft 24 communicates with the inlet 8. The position of the shaft 24 is such that a gap 3.9 exists between the impeller 29 and the diffuser 12.

Liquid entering the inlet 8 is urged by the impeller29 through the passages 24, 23, 25 to the outlet 9. Vanes (not shown) in the passages 24 tend to produce a substantially axial flow of liquid after it has left the impeller 29. A part of the liquid leaving the impeller 29 passes through the gap 34 and the bearings 38, 27, around the windings 23, through the bearings 28, 36 and via the interior of the shaft 34 and the bore 33 to the inlet 8, thereby providing lubrication for the bear ings and assisting in the conduction of heat away from the windings 23.

I claim:

1. An electrically-driven axial-flow pump for a liquid, comprising a casing having an inlet and an outlet and containing a housing which supports the stator and rotor of an electric induction motor, a shaft rotatable in bearings in said housing and forming part of said rotor, an impeller carried by the shaft within the inlet of the casing, an axial passage between the casing and the housing and connecting the inlet and outlet and through which, in use, the greater part of the liquid flows, and a further flow passage interconnecting the upstream and downstream sides of the impeller to direct a part of said liquid past the windings before returning it to the inlet, said further flow passage comprising said bearings in series with a space surrounding said windings whereby that part of said liquid which flows past said windings also flows through said bearings.

2. A pump as claimed in claim I in which the casing and the housing each comprise a plurality of axially aligned parts, the casing parts being formed integrally with the housing parts.

3. A pump as claimed in claim 2 in which the means for directing a part of the liquid through the bearings leave the housing. 

1. An electrically-driven axial-flow pump for a liquid, comprising a casing having an inlet and an outlet and containing a housing which supports the stator and rotor of an electric induction motor, a shaft rotatable iN bearings in said housing and forming part of said rotor, an impeller carried by the shaft within the inlet of the casing, an axial passage between the casing and the housing and connecting the inlet and outlet and through which, in use, the greater part of the liquid flows, and a further flow passage interconnecting the upstream and downstream sides of the impeller to direct a part of said liquid past the windings before returning it to the inlet, said further flow passage comprising said bearings in series with a space surrounding said windings whereby that part of said liquid which flows past said windings also flows through said bearings.
 2. A pump as claimed in claim 1 in which the casing and the housing each comprise a plurality of axially aligned parts, the casing parts being formed integrally with the housing parts.
 3. A pump as claimed in claim 2 in which the means for directing a part of the liquid through the bearings includes a gap between the impeller and one of the housing parts, through which liquid can enter the housing.
 4. A pump as claimed in claim 3 which includes an axial passage within the shaft, through which liquid can leave the housing. 